论文部分内容阅读
【目的】NO-3-N阈值是氮营养状况的评价标准,是蔬菜苗期养分精准管理的重要依据,受品种、施肥、温度、光照等因素的影响。因此,研究不同品种、施肥和外界环境条件下番茄(Lycopersicon esculentum Mill.)幼苗的组织NO-3-N含量的变化程度,以明确番茄幼苗组织NO-3-N阈值,为快速准确诊断幼苗养分状况提供依据。【方法】首先采用穴盘育苗试验,以番茄17个主栽品种为试材,采用水杨酸-硫酸比色法测定了不同组织NO-3-N含量。在该试验基础上,选其中两个品种(‘佳红4号’和‘中杂105号’)继续进行穴盘育苗试验。设施N(26、210、840mg/L),P(4、31、248 mg/L),K(29、234、1875 mg/L),温度(32℃/22℃、28℃/18℃、20℃/10℃),光照(不遮荫、50%遮荫),灌水时间(灌水后2 h取样、灌水后10 h取样、灌水后24 h取样)6因素多水平试验,测定处理后番茄幼苗不同组织中的NO-3-N含量。【结果】番茄幼苗同一品种不同组织NO-3-N含量变化范围为0.79 4.42 g/L,同一组织不同品种间NO-3-N含量变化范围为2.84 4.42 g/L,均达到差异极显著水平;与正常对照相比,氮盈余供应可使组织NO-3-N含量提高1.86倍,而亏缺供应使组织NO-3-N含量降低了97.3%;磷、钾亏缺供应、低温、弱光条件下番茄幼苗组织NO-3-N含量呈降低趋势,最大降低幅度达49.6%,磷、钾盈余供应、高温、灌水时间则因组织NO-3-N含量表现出不同的变化趋势。【结论】番茄幼苗组织NO-3-N含量在多元因素的影响下波动变化。以番茄17个品种不同组织NO-3-N含量为基础值,以环境条件作用最大增幅和最大减幅进行校正,获得番茄幼苗组织NO-3-N含量阈值,即下胚轴1.75 2.72 g/L、茎2.07 4.04 g/L、第1叶位叶柄2.18 4.83 g/L、第1叶位叶片0.62 1.52 g/L、第2叶位叶柄2.31 5.10 g/L、第2叶位叶片0.73 1.50 g/L、第3叶位叶柄2.79 4.09g/L、第3叶位叶片0.40 1.53 g/L、第4叶位叶柄2.44 4.20 g/L、第4叶位叶片0.40 2.13 g/L。
【Objective】 The NO-3-N threshold is the evaluation standard of nitrogen nutrition, which is the important basis for precise nutrient management of vegetables at seedling stage. It is affected by such factors as variety, fertilization, temperature and light. Therefore, we studied the changes of NO-3-N content in tomato (Lycopersicon esculentum Mill.) Seedlings under different varieties, fertilizers and environmental conditions so as to clarify the NO-3-N threshold of tomato seedling tissue. In order to quickly and accurately diagnose seedling nutrient Status provided basis. 【Method】 First, using plug-seedling-raising experiment, 17 main cultivars of tomato were used as test materials, and the contents of NO-3-N in different tissues were determined by salicylic acid-sulfuric acid colorimetry. On the basis of this experiment, two of the varieties (’Jiahong 4’ and ’Zhongza 105’) were selected to continue the plug seedling experiment. (N = 26,210,840 mg / L), P (4,31,248 mg / L), K (29,234,1875 mg / L), temperature (32 ° C / 22 ° C, 28 ° C / 18 ° C, 20 ℃ / 10 ℃), light (no shade, 50% shading), irrigation time (sampling 2 h after sampling, sampling 10 h after irrigation, sampling 24 h after irrigation) NO-3-N content in different tissues of seedlings. 【Result】 The results showed that the content of NO-3-N in different tissues of tomato seedlings varied from 0.79 to 4.42 g / L, and the content of NO-3-N in different tissues of the same tissue varied from 2.84 to 4.42 g / L, Compared with the normal control, nitrogen surplus supply increased the content of NO-3-N by 1.86 times, while the deficient supply reduced the content of NO-3-N by 97.3%. Supply of phosphorus and potassium deficiency, low temperature and weak Under light condition, the content of NO-3-N in tomato seedling decreased with the maximum decrease of 49.6%. The surplus supply of phosphorus and potassium, high temperature and irrigation time showed different changing trend due to NO-3-N content. 【Conclusion】 The content of NO-3-N in tomato seedlings fluctuated under the influence of multiple factors. The content of NO-3-N in different tissues of 17 tomato cultivars was used as the baseline value, and the maximum and minimum amplitude of environmental conditions were corrected to obtain the threshold value of NO-3-N content in tomato seedling tissue, that is, the hypocotyl 1.75 2.72 g / 2.04 4.04 g / L for stem 2.07 g / L, 2.18 4.83 g / L for first leaf position, 0.62 1.52 g / L for first leaf position, 2.31 5.10 g / L for second leaf position, 0.73 1.50 g for second leaf position / L, 2.79 4.09 g / L for the third leaf locus, 0.40 1.53 g / L for the third leaf locus, 2.44 4.20 g / L for the fourth leaf locus, and 0.40 2.13 g / L for the fourth leaf locus.